Textile yaen



April 20, 1937. TAYLQR AL 2,077,441

TEXTILE YARN Filed Sept. 29, 1934 ATTORNEYS smooth character.

Patented Apr. 20, 1937 UNITED sTATEs PATENT OFFICE ton, Spondon, nearDerby, England, assignors to Celanese Corporation of America, acorporation of Delaware Application September 29, 1934, Serial No.746,258 In Great Britain February 5, 1932 9 Claims.

This invention relates to yarns having a basis of continuous filaments,but presenting the appearance of spun yarn, i. e., yarn made from staplefiber.

5 This application is in part a continuation of our application S. No.712,120 filed 20th February, 1934 as a continuation in part of ourapplication S. No. 652,780 filed 21st January, 1933, now Patout No.1,959,142, May 15, 1934.

Spun yarn having a continuous filament basis is usually manufactured bycutting the contin-- uous filaments, e. g. waste filaments, intocomparatively short uniform lengths and then subjecting the staplefibers thus produced to a series of operations similar to those accordedto natural fibers such as cotton or wool, including opening, carding orgilling, drawing, and spinning. The actual operations are appropriate tothe length of the fiber, this being say 1 inches or 2 inches 2 if cottontype machinery is employed, or 3 /2 inches or more if wool or worstedmachinery is employed. Special difilculties arise in the conversion ofthe separate, smooth fibers into. yarn, and the product, since itinvolves the use of a 25 long series of slow operations, is relativelycostly. Moreover, yarns formed by spinning operations of the typeindicated above on preformed fibers (whether naturally occurring fibersor fibers formed by transforming longer filaments or fibers 30 intoshort lengths) are invariably characterized by considerable variation inthickness along their length, some parts containing less fibers in theircross-section than others, and definite slubs appearing at intervals of2 or 3 to feet. Simi- 35 larly, thin places appear at intervals, theoccurrence of the slubs and thin places varying with diiferent classesof yarn. This inability of the ordinary methods of spinning preformedfibers to arrange the fibers in uniform quantity along the length of theyarn produced is' particularly evident on close inspection of woven orknitted fabrics of fine staple fiber yarns made by these methods.

Thus, in ordinary spun yarns, slubs occur hav- 45 ing a diameter up to50 or 100% or even more in excess of the diameter of the yarn adjacentto the slubs, and such change in diameter is readily apparent in fabricsin which the yarns are employed, particularly when the fabrics are offine, Again, the yarns may have thin places with a diameter as low as 70or even 50% of the adjacent yarn.

The yarn according to the present invention is one which, while havingthe general appearance and other valuable properties of spun yarn,comprises cut filaments twisted together, the yarn being free fromdepartures in diameter of more than 20% as compared with the averagediameter of the yarn, that is to. say, any thickened or thinned placesin the yarn show at the most a variation in diameter of about 20% fromthe portions of the yarn immediately adjacent such places. The yarn mayevenhave variations in diameter of no more than or even less than 10%.Variations of the order mentioned are so small that the yarn for mostpractical purposes can be regarded as uniform.

This uniformity is a particularly valuable property of the yarn.Moreover, since the fibers in the yarn consist of cut filaments, theyhave substantially the same physical properties as the original uncutfilaments; in particular, the original extensibility of the material isretained in the fibers which may, therefore, havev an extensibility ofsay 12, 14, 16 or 20%, depending upon the extensibility of the originalfilaments. The high extensibility of the new yarn is a factor of Iconsiderable value both as regards the applicability of the yarn tosubsequent textile operations and the elasticity and softness ofproducts containing the yarn.

By reason of these important factors the yarn according to theinvention, though of a fibrous character, possesses features previouslyfound only in continuous filament yarns, andin particular thefilamentous fibers of the yarn are disposed with a uniformity closelycomparable with that of continuous filament yarn.

' The fibers formed by subjecting a bundle of continuous filaments to acutting action in the production of the new yarn may be of varyinglength, yet, notwithstanding this, uniformity of the order stated mayreadily be obtained, the numbers of fibers at all points in the lengthof the yarn being the same as the number of filamerits in theoriginalbundle, subject to any small displacement that may take place of fibersor loose ends of fibers.

The product may have any desired degree of twist, appropriate to the useto which it is to be put. Quite a surprising strength is obtained withonly a low degree of twist, and the elasticity and softness arecorrespondingly high.

The range of fiber length in any particular yarn may be considerable,there, however, usually being a preponderating number of fibers thelength of which is near the average fiber length, with a number offibers of greater and lesser length than that of this preponderatingnumber. Notwithstanding this variation in length, the appearance of theyarn of a particular average length of fiber is very similar to that ofordinary spun yarns composed of fibers the uniform length of which issubstantially the same as such average length. Thus, a yarn according tothe invention composed of artificial filaments cut into lengths rangingfrom say 3 inches to 20 inches or 22 inches and' having an average fiberlength of about 8 inches is very like a worsted yarn all the fibers ofwhich are about 8 inches in length.

The considerable strength of the yarns according to the invention isprobably due to the assistance afforded by the cut filaments of morethan the average lengthin holding all the filaments together. This isnoticeable by comparison with spun yarn made by the ordinary methodsfrom out fibers of uniform length, the yarn according to the inventionhaving .a similar strength .to that of ordinary yarn of much highertwist. As previously indicated, this results in the new yarn exhibitinga high degree of elasticity and softness.

Apart from the high quality of the yarn as regards strength, elasticity,and softness, the yarn enables fabrics to be made that are surprisinglyeven in character and particularly pleasing because of their freedomfrom objectionable slubs or streaks.

The yarn may consist of cut filaments of a wide variety of material,both natural and artificial, for example filaments of natural silk, orartificial filaments of cellulose acetate or other organic derivativesof cellulose, e. g. other cellulose esters, such as cellulose formate,propionate and butyrate, and cellulose ethers, such as ethyl and benzylcellulose, and reconstituted cellulose such as viscose, nitrocelluloseand cuprammonium artificial silk. It may likewise consist of a mixtureof two or more of the above types. One such yarn may be doubled with oneor more other yarns of any desired type. For example, two or more of theyarns containing the cut filaments may be doubled together for thepurpose of increasing the denier or counts of the yarn and improving theregularity, or for any other purpose such as the production of yarncontaining filaments or fibers having different dyeing properties. Thus,cellulose acetate fibrous yarn may be doubled with similarly formedfibrous yarn of natural silk or reconstituted cellulose artificial silk,orwith ordinary continuous filament or fibrous yarns.

Where the basic yarn consists of artificial filaments, these may be ofalustrous character, or they may be of subdued or reduced luster.Filaments of different luster may be contained in a single yarn.

The yarns according to the invention have a wide range of application inthe textile industry, whether used lone orin conjunction with othermaterials in the manufacture of woven, knitted, or otherwise formedfabrics or articles. For example, with average fiber lengthscorresponding to thefiber lengths of wool of various grades, the yarnsare particularly suitable for knitting fabrics ranging from therelatively heavy to those ordinarily obtainable only by the use of thevery costly fine woolen yarns. At the same time, there can be obtainedsuch advantages as, for example, controlled luster and, in. the case ofcellulose acetate yarns, low shrink-- ing peculiar to the materials ofwhich the yarns are composed.

The yarns can be prepared from the continuous filament materials in anumber of ways by simple operations which, while breaking the continuityof individual filaments, do not interfere with the continuity of thematerial as a whole. These operations involve subjecting a bundle ofcontinuous filaments to a cutting action occurring more or less atrandom among the individual filaments of the bundle so as to sever thefilaments into lengths. A certain amount of initial twist and/ or theaddition of twist during the operation enables the points of cutting tobe distributed among the several filaments of the bundle.

Various methods of producing the yarns according to the invention willnow be described with reference to the accompanying drawing, in which-Fig. 1 shows the conversion of a continuous filament yarn following itswithdrawal from a twisting spindle;

Fig. 2 shows the conversion of a yarn as it is being delivered to atwisting and winding device;

Fig. 3 isa plan view of a detail of Fig. 2;

Fig. 4 shows a different type of apparatus in which use is made of thespecial roller arrangement shown in Fig. 5; 1

Fig. 6 shows an apparatus generally similar to that shown in Fig. 4 butmodified in various respects; and

Fig. 7 shows an apparatus making use of an endless abrasive band.

Referring to Fig. 1, a yarn ll] of say 250 or 300 denier is drawn from abobbin ll rotated so as to impart say 5, 8, or 10 turns per inch oftwist to the yarn. The twisted yarn is led over a roller I2 covered withan abrasive l3 such as emery or glass paper, the yarn being drawn at apredetermined rate by means of a take-up device I4.

Because the yarn l l is drawn over the abrasive I3, its severalfilaments are subjected to the cutting action of the abrasive particles.Since, more over, the yarn is being twisted by the rotation of thebobbin II, the yarn itself is rotating as it passes over the abrasive,so that different filaments in turn are subjected to the cutting action.Upon any particular filament, the frequency of cutting is somewhatirregular, due to the irregular nature of the abrasive material and tothe irregularity with which any filament comes into contact with acutting particle. The continuous filaments are therefore severed intofibers of varying length.

At any one point in the yarn, at the most only a few of the filamentsare severed, and continuity of the yarn is therefore maintained. Controlover the average length of fiber may be effected by regulating the rateof passage of the yarn I I over the roller I2 and by varying the rate ofrotation of the roller.

, In Fig. 2 a yarn [5 is taken at a predetermined rate by a feedrollerl6 from any suitable supply, e. g. a dry-spinning apparatus I1, and fedto a twisting apparatus such as the cap-spinning apparatus l8. Inpassing from the balloon guide 19 to the edge of the cap 20 and so on tothe bobbin 2|, the yarn forms a balloon 22 rotating round the cap.Between the guide I9 and the top of the cap, the yarn passes through theopening of a ring 23, and is carried against a series of teeth 24 formedby notching the inner edge of the ring.

In the balloon'22 the yarn is receiving twist and thus rotates uponitself as it passes over the teeth 24. At the same time the yarn istravelling endwise'as it is being wound on the bobbin 2|. Thereforedifferent filaments of the yarn come in turn into contact with the teeth24 and the filaments are converted into fibers of varying length. Thetwist imparted during the operation firmly binds the filaments into acoherent yarn.

In starting the operation, the yarn is passed through the slot in thering 23, and then retates in the direction shown by the arrow. Thefrequency of cut depends on the number of teeth 24 in the ring 23, therate of feed of the yarn, and the rate of twisting.

Referring now to Fig. 4, this shows an entirely different method ofeffecting the cutting of the filaments. The yarn 26 is led from anysuitable source, e. g. the bobbin 21, to a pair of rollers 28, 29, ofwhich the roller 29 is fluted (being preferably of metal) while theroller 29 consists of a resilient core 30, e. g. of soft rubber orsponge rubber, surrounded by a flexible sleeve 3|. The roller 29 presseslightly on the fluted roller 28, preferably by its own weight.

Below the roller pair 28, 29 is a second pair of rollers 32, 33, theroller 32 being fluted and the roller 33 surfaced with material such asrubber or leather. The roller 33 presses heavily against the roller 32,the pressure in conjunction with the fluted surface of the one rollerand the resilient surface of the other causing the yarn to be firmlygripped as it passes between the rollers after leaving the first pair28, 29.

To provide for this pressure, the roller 33 is carried on a dependingarm 34 pivoted at 35, to which arm is connected a cord or the like 36carrying a weight 31.

The roller 32 is driven at a speed considerably higher than the speed atwhich the roller 28 is driven, and, because of the firm pressure appliedby the roller 33, tends to draw the yarn 26 through the rollers 28, 29at a speed much greater than the peripheral speed of the rollers. Only alight pressure being exerted on the yarn by the roller 29 to press theyarn against the flutes of the roller 28 and the resilient core of theroller 29 en-- abling the flexible surface 3| of the roller to givesomewhat, the rollers 28, 29 slip on the faster moving yarn.

The filaments" of the yarn are thus subjected to a slipping grip action,the flexible covering of the roller 29 nipping filaments in turn againstthe flutes of the roller 28 and cutting them cleanly.

A slight degree of twist in the yarn 26 enables the points of cutting tobe well distributed over the yarn, but, by reason of" the randomincidence of the cutting, the filaments are severed into fibers of alength which may vary in accordance with such factors as the speed ofthe operation, the difference in speed between the two pairs of rollers,the twist in the yarn, the size of the filaments, and the pressureexerted on the filaments at the first pair of rollers. For example,higher operating speed and/or lower pressure on the filaments mayproduce greater variations between the fiber lengths of a particularstaple fiber product than lower speed and/or higher pressure. Controlover the appearance and properties of the product may therefore beobtained by suitable adjustment of the operating conditions.

Preferably, the pressure at the rollers 32, 33 is sufliciently high toavoid slippage of the material in passing through these rollers, so thatthe linear output of the apparatus is substantially equal to theperipheral speed of the rollers 32, 33. Very light pressure by theroller 29 enables the yarn to be withdrawn from the bobbin 2! atsubstantially the same speed as that at which it leaves the rollers, thedenier or count of the material being substantially unchanged in theoperation.

On leaving the rollers 32, 33, the filaments now converted into fibersare twisted and wound by the cap-spinning device 38.

In Fig. 6, the yarn 39 is drawn from a bobbin 40 rotated to impart say 3turns per inch of twist to the yarn. The twisted yarn passes through twopairs of rollers 4|, 42 and 43, 44, the rollers 4|, 43 being flutedsimilarly to the rollers 28, 32 of Fig. 4 and driven with a similardifference of speed, and the rollers 42, 44 being similar to the rollers29, 33 respectively of Fig. 4.

Both rollers 42, 44 are carried by a frame 45 on an arm 46 pivoted at41, a cord or the like 48 loaded with a weight 49 being connected to theframe 45 to cause each roller to engage with any desired pressureagainst its corresponding roller 4| or 43. As with Fig. 4, the rollers43, 44 draw the yarn 39 through the rollers 4| 42, these latter slippingon the yarn and cutting the filaments into fibers of varying length.

Some at least of the twist in the yarn as it reaches the rollers 4|, 42is retained after conversion of the filaments into fiber. Further twistmay be added after the yarn leaves the rollers 43, 44.- In Fig. 6, suchfurther twist is imparted by the ring spinning device 50.

Referring to Fig. 7, a bundle of filaments 5| is fed between a roller 52and an endless abrasive band 53 guided by rollers 54 and led over aroller 55, any or all of the rollers serving to drive the band. Theroller 55 supports the band 53 at the point where the bundle 5| ispressed against it by the roller 52. The bundle is drawn past the band53 and roller 52 by means of a pair of rollers 56, 51, which exert afirm grip on the bundle and f are driven at a peripheral speed in excessof that of the band 53 so that the bundle is caused to slip over thesurface of the band.

By reason of the pressure between the roller 52 andthe band 53(supported by the roller 55) and the slip permitted by these members,the bundle drawn between the roller and the band has its filamentssevered at frequent intervals so that after leaving the cutting pointthe bundle contains staple fibers.

Instead of the roller 29 or 42 being resilient, it may be rigid butlight in weight so as to apply only a light pressure to the filaments.Again such roller may itself have a cutting action on the filaments.

Since the yarn treated in the apparatus shown in Figs. 4, 6 and 7 isconverted into fibers by a cutting action resulting from light pressureof the filaments of the yarn against a cutting surface (the filamentsbeing able to slip over the cutting surface), the fibers havesubstantially the same extensibility as the original filaments. Forexample, continuous filament yarn of from 16-20% extension converted inthis way into fibrous yarn gives an extension in the final yarn (twistedto 2 -5 turns per inch) of from 12-14%, which makes the yarns veryeasily handled in knitting, weaving etc. and gives fabrics having a softhandle.

The conversion of the filaments into fibers by a cutting action isimportant, not only because it provides for the substantial uniformityin weight of the staple fiber yarn, but also because it enables thefibers to remain elastic and soft in handle, This result cannot beachieved by any conversion operation relying on tensioning the filamentsto breaking point, since the stretching of the filaments before breakagevery materially reduces their extensibility; the fibers thus producedare hard and wiry, and fabrics made from yarns containing the fibers areextremely harsh in handle.

The continuous fibrous material produced from the plurality ofcontinuous filaments has at least sufficient twist to bring aboutcohesion between the fibers and therefore to maintain its continuity. Itmay have such twist immediately upon the conversion of the filamentsinto fibers to enable it to be used as yarn in textile operations or, insome cases, further twist may have to be added, e. g. if harder orstronger yarns are required. It is therefore to be understood that theterm yarn is employed in the appended claims to connote a continuousfibrous material whether such continuous material is lightly twisted orpossesses a higher degree of twist.

What we claim and desire to secure by Letters Patent is:--

1. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments in which at least apart of each cut filament occupies substantially the same position withrespect to its neighbors that it had prior to cutting.

2. A continuous fibrous yarn of cellulose acetate derived from a bundleof continuous filaments and composed entirely of out filaments in whichat least a part of each cut filament occupies substantially the sameposition with respect to its neighbors that it had prior to cutting.

3. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments in which at least apart of each cut filament occupies substantially the same position withrespect to its neighbors that it had prior to cutting, said yarn beingfree from diameter variations in excess of 20% of the average diameterof the yarn.

4. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments of varying length in'which at least a part of each cut filament occupies substantially thesame position with respect to its neighbors that it had prior tocutting.

5. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments of varying length inwhich at least a part of each cut filament occupies substantially thesame position with respect to its neighbors that it had prior tocutting, said yarn having substantially the same uniformity of diameteras a continuous filament yarn.

6. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments in which at leasta partof each cut filament occupies substantially the same position withrespect to its neighbors that it had prior to cutting, the cut filamentsbeing of varying length, the average length of said filaments beingsubstantially equal to the length of wool fibers.

7. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed enof each cut filament occupies substantially thesame position with respect to its neighbors that it had prior tocutting, the cut filaments being of varying length, the longer andshorter filaments being substantially uniformly distributed throughoutthe length of the yarn.

8. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments in which at least apart of each cut filament occupies substantially the same position withrespect to its neighbors that it had prior to cutting, said yarn havingan extensibility of at least 12%.

9. A continuous fibrous yarn derived from a bundle of continuousfilaments and composed entirely of cut filaments in which at least apart of each cut filament occupies substantially the same position withrespect to its neighbors that it had prior to cutting, the cut filamentsbeing of varying length, there being a preponderating number of cutfilaments substantially equal to the average length and a small numberof cut filaments of a length greater and less than said average length,said yarn being free from diameter variations in excess of 20% of theaverage diameter of the yarn.

MATTHEW MICHAEL TAYLOR. STEPHEN MILLER FULTON.

